1. Field of the Invention
The present invention relates to differentiating devices and systems for differentiating singular units from a stack of a plurality of units, useful for separating and dispensing single units, one at a time from a stack of a plurality of such units in vending machines and the like.
2. Prior Art
Devices and systems for differentiating single units from a stack of a plurality of units is well known. In the apparel manufacturing industry, automated assembly of apparel is made practical because of the use of differentiating devices. Such devices separate single units of pre-cut patterns from a stack of a plurality of units of similar pre-cut patterns of material. Vending machines, which dispense merchandise in single units or packages, use a differentiating system for separating a single item or package, from a plurality of similar items or packages, for dispensing the differentiated item to a purchaser using the vending machine to make such purchase.
The character of the packaging of the merchandise presented for sale in a vending machine influences the structure of the differentiating device. Differentiating a single unit from a plurality of units, such as in a vending machine, must be accomplished without defacing or damaging the package retaining the goods and the goods must be presented to the purchaser undamaged. Endless belts, supporting spaced pushers, have been used to separate a single unit from a plurality of units but the belt surface between the spaced pushers must be slippery to the surface of the packaging in order to avoid separating more than one package at a time from the stack of packages. Further, the spacing of the spaced pushers attached to the endless belt must be precisely measured, relative to the size of the package to be differentiated and strongly secured to the endless belt. The number of pushers secured to the endless belt is controlled by the space between pushers and the length of the belt. The length of the belt is limited by the width of the vending machine. These factors limit greatly the size of the package that may be handled by the differentiator.